Electric wiring system and apparatus



June 17 1924. 1,497,775

: w. A. DUNN ELECTRIC WIRING SYSTEM AND APPARATUS Filed March 27, 1922 OVEKLCAD ELM:

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Quill/100"",

" INVENTOR ATTORNEY Patented June 17, 1924.

UNITED STATES 1,497,775 PATENT OFFICE.

WARD A. DUNN, 0F OGDEN, UTAH.

ELECTRIC WIRING SYSTEM AND APPARATUS.

Application filed March 27, 1922. Serial No. 546,978.

, Systems and Apparatus, of which the fol lowing is a specification.

My invention relates to electric motors' and has for its object to provide a safety device to prevent the burning out of an electric motor while in operation of either the two-phase or three-phase type should any one of the four main fuses of the twophase type or any one of the three main fuses of the three-phase type be burned out, leaving the motor operating on the other phase or phases, and particularly to provide an auxiliary fuse for each main fuse and which auxiliary fuses are connected in series with the under voltage release circuit, whereby the release circuit is broken before any injury may occur to the motor, thus releasing the main motor circuit contacts of the auto starter, compensator or switch.

These objects I accomplish with the device and wiring connected therewith which is illustrated in the accompanying'drawings in which similar letters and numerals of reference indicate like parts throughout the several views and as described in the specification forming a part of this application and pointed out in the appended claim.

In the drawings in. which I have shown a substantial embodiment of my invention Figure 1 is a diagrammatic view showing the electric circuits and parts of the apparatus as applied on a three-phase motor. Figure 2 is a similar View as used on a twophase motor. Figure 3 is an elevation of my auxiliary fuse shown applied to any main motor cartridge fuse, parts shown in section. Figure 4: is a plan view showing the bottom of the auxiliary fuse applied to any main motor cartridge fuse, with parts cut away. Figure 5 is a transverse section on line 5-5 Figure 3. Figure 6 is a diametrical longitudinal section of the sockets and wire used to connect the fuses in series, parts cut away.

It is well known that any two-phase or three-phase motor in operation, unless over loaded, will continue to run on the other phase or phases when fromany cause one of the main motor fuses is blown out or destroyed, and injury to the extent of burning outthe motor will result unless the motor is stopped. And it is the main feature of the present invention to use an auxiliary fuse, in conjunction with each and all of the main fuses, to provide a positive method and means for opening the under voltage release circuit, thereby automatically releasingthe main motor contacts of the autostarter, compensator or switch immediately on the blowing of any one of the main fuses. This is accomplished by providing a low amperage auxiliary fuse in close proximity to and for each of the main fuses, which auxiliary fuse is of sufficient size to only carry the small current of the under voltage release circuit, which low amperage auxiliary fuses are connected in series, and so positioned in relation to the main fuses that when either of the main fuses are blown out, the are caused by the blowing or burning in two of the main fuses, or the melting and separation of the main fuse, which separated ends or end, while still overheated, willdrop down against the adjacent auxiliary low amperage fuse short circuiting the under voltage release circuit, thereby instantly burning said auxiliary fuse in two, thus instantly opening the under voltage release circuit, which immediately operates the under voltage release mechanism and releases the main motor contacts of the auto-starter, compensator or switch before any damage can result.

The present invention consists of a fuse cartridge shell A of cylindrical form within which is a longitudinally disposed main fuse 1 with contact caps B with which said fuse is connected. In the bottom of the cylindrical wall of said shell A are inserted two auxiliary fuse cases C at practically right angles to said shell A, with a portion of the inner ends cut away as at 2. An auxiliary fuse 4 is positioned centrally in each of said cases G and then bent at right angles and run parallel with said main fuse from one of said cases 0 to the other. The said auxiliary fuses are of light amperage, as they are intented to only carry the current required to operate the under voltage release mechanism and are to be burned in two by the are produced by the blowing or burning in two of the main motor fuse 1, or this failing to break the auxiliary fuse, the remaining burned and overheated ends of the destroyed main fuse dropping down against said auxiliary fuse thereby short circuiting the under voltage release circuit,

is running under normal or greater load A connection is made between said auxili ary fuse terminalsby the wire. 5, the. ends of which are secured in the sockets D, which sockets are to be pushed over the external c ends of said cases G, making contact with terminal of fuse 4;, but any form ofconnectijon may be used between said terminals of fuses; 4:, to place them in series. Any form of connection may then be used to. connect-one terminal end of the series composed of fuses; 4 to one main motor circuit wire; this connectior to said motor, circuit wire tobe made between the main fuses and the auto-starter, compensator or: switch.

Elie under voltage release circuit, isthen completed through the series of fuses l by connecting the remaining terminal of said series of fuses 1 through. the overload relay (if one is use d.) thence; through the under voltage release 1n series, thence back into one of the other ma n motor circu t wires,

connection with said wire to be made between rnain meter fuses and ante-starter, compensator or swltch; c

P en nd 1a m= The operation of my system of connectingthe wires and using myapparatus is as follows:

The auxiliary fuses are parallel with and in close proximity with the main fuses for motors of the class described, and said auxiliary fuses are connected in series, and the auxiliary fuses are connected with the under voltage release coil of the auto-starter, compensator or switch, in order that should any one of the main fuses 1 be blown out, the, of the main fuse at the instant it blows or by one or both remaining ends of the fuse dropping. against the auxilfuse causing a short circuit in the under voltage release circuit, thereby causing the auxiliary fuse to be. burnedin two and openi'ngthe, under voltage release circuit.

Having.- thus described my system of wiri a d e ppar t s y hi it mayb carried out, I desire to secure. by Letters n appara u or Pr tecting a. mul p pha e moto mpr s g a c r dg fus sh ll, of a a n f e carried: n, s id ll; two auxiliary fuse cases. in the sidewall of said shell a. fuse of less amperage connected with said cases; and. caltl isd in, said shell parallelwithsaid. main fuse.

In testimony whereof I have afiixedj my igna urea i W RD A-DU' 7 

